Drybar, the fast-growing chain of hair styling salons that specialize in blow-drys only, expects to serve customer number 1,111,111 sometime this week.

Whoever that lucky customer is will receive free monthly blow-drys for life.

And for everyone else, the company is offering a free blow-dry to anyone who purchases $100 worth of Drybar branded products or tools, either online or in a salon, through Sunday.

The offer is good at all Drybars nationwide. Since opening its first salon in February 2010 in Los Angeles' Brentwood neighborhood, Drybar has expanded to 28 salons in California; Atlanta; Phoenix and Scottsdale, Ariz.; New York and Washington, D.C. And new shops are planned this year in Chicago, Boston and Houston, the company says.

"I cannot believe what our little business has grown into," company founder Allie Webb said in a news release about the promotion. "I am so unbelievably grateful to our clients, friends and stylists who have helped us get here."